Technological parameters of carp growing (Cyprinus carpio) at different stocking densities

Abstract

This article presents a study of the technology of growing carp (Cyprinus carpio) using different stocking densities in feeding ponds. Carp is one of the most common and essential freshwater fish species for commercial farming and consumption. The study was conducted over several months, with an assessment of carp's growth, survival, and productivity when using different stocking densities in feeding ponds. Different stocking densities included low (sparse), medium, and high (dense) carp individuals per unit area. To experiment, four groups of carp individuals were kept in feeding ponds at different stocking densities from 2,000 to 3,500 specimens per hectare of water area. Using extensive planting material of carp with an average weight of 55 g makes it possible to obtain commercial carp with an average weight of 485 g to 650 g during a two-year cycle of cultivation in the conditions of the second fish farming zone without reducing fish production. At the same time, the largest concentration of carp was obtained in a pond with sparse planting of annuals – 2.0 thousand specimens/ha. An increase in the planting density of yearlings of carp to 3.5 thousand units/ha led to a decrease in the average daily weight of two-year-old carp to 510 g while maintaining a high fish production of 1122 kg/ha. At the same time, a hydrochemical analysis was carried out in the ponds, and the amount and biomass of the natural feed base (phyto-, zooplankton, and zoobenthos) were determined. The analysis of the research results indicates that the stocking density of carp has a significant impact on its productivity. The sparse stocking conditions promoted more significant growth and better development of the fish, which may be due to less competition for food and space. On the other hand, high stocking density led to a slight decrease in growth and did not affect survival and fish productivity. The results of this study have practical applications for fish farms engaged in the cultivation of carp. They emphasize the importance of an optimal balance between the number of fish, the availability of natural feed, and the area of the feeding ponds in order to achieve maximum growth and productivity with minimum costs of keeping and feeding the fish. Such research will help improve fish farming technologies and optimize production processes to ensure sustainable and efficient development of the industry.